Normalized Modeling of Piezoelectric Energy Harvester Based on Equivalence Transformation and Unit-Less Parameters

摘要

Micro-electromechanical systems are ubiquitous in several energy harvesting solutions and can be used in applications such as bio-implantable devices and wireless micro-sensors. Piezoelectricity is an interesting key to perform the interface between environmental extracted energy and the power delivered to the load due to the use of mechanical vibration and resonance features. However, it is necessary for a detailed analysis in order to obtain an accurate understanding of the system. In this regard, some works deal with the normalization procedures to analyze the piezoelectric component behavior based on the mechanical resonance frequency. In order to enhance the system modeling, the electromechanical resonance frequency must also be analyzed. This paper deals with an approach to model the piezoelectric component that allows analyzing several unitless parameters that are critical to improve the performance of the system. In addition, a state-space model for the piezo-harvester based on the Class-E resonant rectifier is presented. Some experimental results are shown to validate the theoretical approach.